Since the first days of heavier-than air flight, the airplanes had one prominent universal characteristic—the wings. While winged flight has proved efficient as humanity's first step in understanding and recreating flight, the requirements of modern aviation are pushing the concept of winged flight to its limit, making the wing a limiting factor in advancement of powered flight.
The wings are constructively-complex and bulky elements, with numerous compromises inherent in any wing design. Wings are often the largest part of an airplane, and often the most important in determining storage and utilization costs. The wings limit the speed characteristics of an airplane. Wings have a strength threshold and are prone to tearing off at excessive speeds or load. The effects of turbulence and convective jets on the plane's fuselage are multiplied by the length of the wing, as through by a lever. These wing-magnified effects significantly contribute to wear of the aircraft and appearance of microscopic cracks on the fuselage, as well as on the wings themselves. This wear in turn significantly affects the safety of flight.
Wing has a number of aerodynamic deficiencies. For example, the form of the wing, accepted as optimal on today's airplanes is voluminous towards the front. While providing some advantages, this also creates disadvantages, such as increased resistance to the flow of oncoming air current. It also causes turbulence behind the wing, which in turn negatively effects flight characteristics and, overall, decreases fuel efficiency. The wing also has to be positioned at a considerable angle toward the oncoming air flow to provide a lifting stabilizing force, holding the plane suspended in mid-air. This also necessarily creates tremendous resistance on the wing, accelerating wear and lowering efficiency.
Swept wings of the modern aircraft allow for some reduction of drag at the cost of creating other problems. At high speeds, there is no time for airflow to react to redistribution, and air flow over the wing is virtually unaffected by the shape of the wing. At slower speeds, a problem of spanwise flow develops, where most of the air toward the tips of the wings moves along the wing, not over it, thus creating a dangerous reduction in lift. This in turn leads to unpredictable stalls, particularly dangerous at landing speeds, and known as “Sabre dance.” Swept wings are also complex in production, show increased drag at slow speed, and apply significant torque to fuselage.
Necessary compromises in the length of the wing, greatly limit the operational height of the airplanes. At high altitudes, the wings provide insufficient lift, leading to unpredictable and fatal stalls. Yet it is at these high altitudes, that the airplane, particularly one with jet or rocket engines, will encounter the least drag, and can travel at highest speeds and with greatest efficiently. Limited lift of conventional wings also negatively affects maneuverability of the planes. Sharp turns, sometimes necessary to avoid collision or adjust heading at slow speeds often lead to unrecoverable stalls.
Wings are lightweight, flexible and fragile. Yet, there is no alternative on most of the planes of modern design, with narrow fuselage and wide wings, but to position at least some of the landing gear on the wings. Yet, wings cannot bear heavy weight or excessive stress. Thus the design of the landing gear—an element critically important to safety has to be compromised. Ideally, the right and left sections of the gear must be separated as far as possible to provide the maximum balance for a landing airplane. Yet the fragile tips of the wings can not bear the weight or the plane and the shock of landing transferred through the landing gear. The gear has to be positioned close to the fuselage, compromising stability, particularly during high-wind landings and take-offs. To fit in the wings, the gear itself has to be small, and lightweight, lacking proper shock-absorbing capacity. Yet, the gear must be long enough to accommodate low-hanging engines and the bottom of the fuselage. These compromises limit the effectiveness and safety of the gear and restrict landings to smooth concrete surfaces.
Limited area of the wing leads to large wingspans, which in turn limits takeoffs and landings only to specially-prepared wide strips. Landings, of passenger planes, even on wide highways with trees or poles on the sides, are often impossible. Large winged planes also require airstrips of great length, often three to four miles long, to achieve minimal takeoff speed of 220-280 km/hr. Achievement of such speeds by a multi-ton giant, on the ground, is inherently dangerous. Slightest mistakes by the pilots, debris on the runway, blown gear tire, can all lead to a disaster. The danger is further exacerbated by inadequate compromised gear of modern airplanes. Furthermore, such speeds on the ground create tremendous stress on the gear, and the structure of the airplane, contributing to wear.
Traditional airplane construction has a long narrow fuselage and a tail part, usually comprised of three rudder wings. These rudder wings carry out the function of in-flight stabilization and provide for maneuverability. These separately-positioned rudders create additional drag and reduce efficiency. Further, the front of the fuselage of most transport and passenger planes have a very low fineness ratio inherent in the design, thus encountering tremendous drag at airborne speeds. Similarly, the wings can not have a high fineness ratio, to ensure sufficient lift coefficient.
As a result of this resistance to airstreams/drag, inherent in modern airplane designs, the speeds of travel are limited. Numerous curvatures and surfaces perpendicular to air streams, common in modern airplanes not only reduce the efficiency of the plane, but also lead to loud shock waves and great loss of energy as aircraft nears the speed of sound. Furthermore, at high speeds, such as those encountered by high-speed airplanes and space shuttles (of basic winged airplane design), the drag produces enormous heat, requiring the use of expensive and often heavy and unreliable thermal protection materials on the body of the plane.
The length of the fuselage, particularly on longer passenger and transport planes severely limits the take-off angle. An excessive take-off angle causes the rear of the airplane to strike and scratch the ground. Limited take-off angle further necessitates and limits airplanes, even those with engines powerful enough for steep take-off, to longer runways.
The structure of the modern airplanes, greatly favors, and often necessitates, the placement of engines below the wings. This seriously hinders emergency landings, particularly on water. The engines, dipping into the water during the landing, usually tear off the wings and destroy the fuselage.
The aviation's requirements for more powerful, reliable and quite engines necessitates larger engine sizes. Larger heavier engines require thicker and longer wings, which further increases the weight of the airplane and the drag. Due to the necessary placement under the wing of the airplane, the diameter of the engine is limited to less than the height of the plane's wings above the ground. The solution to the latter problem was found in increasing the height of the landing gear, and thus raising the wings higher above the ground. Yet, this in turn further increases the overall weight of the airplane and raises the center of gravity. The result is further decrease of plane's stability on the ground, complicated servicing, impossibility of belly landings in cases of gear malfunction, and overall decrease in safety.
The tubular vehicle of the present invention overcomes all of the shortcomings of winged airplanes, described above. In addition, the design of the tubular vehicle provides some distinct advantages. For example, it allows for creation of the plane of high constructive rigidity, with vehicle being compressed together at high speeds and sharp turns, instead of being pulled apart, as with today's aircraft. The tubular vehicle allows for high fineness ratio of all parts, including the nose part of the airplane, allowing for efficient flight at all heights and speeds, including supersonic speeds. The new design allows for more efficient rudders and maneuverability. It allows for greatly improved load capacity and planing ability at the same time. It allows for larger, simpler, and more reliable gear. It allows for combination or separate use of turbines and rocket engines to allow the use of the new vehicle in upper stratosphere and as a space shuttle.
The new design allows for takeoffs at extreme angles and nearly vertical landings. Furthermore, as most of the planing surfaces of the tubular vehicle are in or on the body of the vehicle itself, there is no need for long wings. This, in combination with capacity for better landing gear would allow for landing on narrow roads and rough landing strips. The new vehicle would not require the enormous hangar spaces necessary for today's aircraft, all leading to greatly reduced investments in upkeep and infrastructure.
The adherence to the traditional wing design has stalled the development of aviation in the last half a century. While most fields of technology have experienced radical revolutions in recent decades, there is very little difference in speed, comfort and safety characteristics between the airplanes designed in the 1960s and those being made today. In the era of open borders and global economies, a new type of an airplane is required that would overcome the limitations and compromises inherent in the design of today's aircraft and allow for further development of aviation. The tubular vehicle of the present invention achieves this objective and provides numerous other benefits.